Fetal and adult human oligodendrocyte progenitor cell isolates myelinate the congenitally dysmyelinated brain.

Both late-gestation and adult human forebrain contain large numbers of oligodendrocyte progenitor cells (OPCs). These cells may be identified by their A2B5(+)PSA-NCAM(-) phenotype (positive for the early oligodendrocyte marker A2B5 and negative for the polysialylated neural cell adhesion molecule). We used dual-color fluorescence-activated cell sorting (FACS) to extract OPCs from 21- to 23-week-old fetal human forebrain, and A2B5 selection to extract these cells from adult white matter. When xenografted to the forebrains of newborn shiverer mice, fetal OPCs dispersed throughout the white matter and developed into oligodendrocytes and astrocytes. By 12 weeks, the host brains showed extensive myelin production, compaction and axonal myelination. Isolates of OPCs derived from adult human white matter also myelinated shiverer mouse brain, but much more rapidly than their fetal counterparts, achieving widespread and dense myelin basic protein (MBP) expression by 4 weeks after grafting. Adult OPCs generated oligodendrocytes more efficiently than fetal OPCs, and ensheathed more host axons per donor cell than fetal cells. Both fetal and adult OPC phenotypes mediated the extensive and robust myelination of congenitally dysmyelinated host brain, although their differences suggested their use for different disease targets.

Telomerase immortalization of neuronally restricted progenitor cells derived from the human fetal spinal cord.

Lineage-restricted progenitors of the central nervous system (CNS) are not readily expandable because their mitotic competence is limited. Here we used retroviral overexpression of human telomerase reverse transcriptase (hTERT) to immortalize progenitors from human fetal spinal cord. The hTERT-immortalized cells divided in basic fibroblast growth factor (bFGF) expressed high telomerase activity, and gave rise to phenotypically restricted subpopulations of either glia or neurons. The latter included a prototypic line, hSC11V-TERT, that gave rise only to neurons. These included both chx10(+) interneurons and Islet1(+)/Hb9(+)/ChAT(+) motor neurons; the latter were recognized by green fluorescent protein (GFP) driven by the Hb9 enhancer. The neurons were postmitotic and achieved electrophysiologic competence. Upon xenograft to both fetal rat brain and injured adult spinal cord, they matured as neurons and survived for 6 months, with no evident tumorigenesis. The cells have survived >168 doublings in vitro, with karyotypic normalcy and without replicative senescence. hTERT overexpression thus permits the generation of progenitor lines able to give rise to phenotypically restricted neurons.

Fetal stromal-dependent paracrine and intracrine vascular endothelial growth factor-a/vascular endothelial growth factor receptor-1 signaling promotes proliferation and motility of human primary myeloma cells.

Induction of neoangiogenesis plays an important role in the pathogenesis of multiple myeloma. However, the mechanism by which expression of vascular endothelial growth factor (VEGF)-A and its receptors modulate the interaction of multiple myeloma cells with stromal cells is not known. Here, we describe a novel in vitro coculture system using fetal bone stromal cells as a feeder layer, which facilitates the survival and growth of human primary multiple myeloma cells. We show that stromal-dependent paracrine VEGF-A signaling promotes proliferation of human primary multiple myeloma cells. Primary multiple myeloma cells only expressed functional VEGF receptor (VEGFR)-1, but not VEGFR-2 or VEGFR-3. VEGFR-1 expression was detected in the cytoplasm and the nuclei of proliferating multiple myeloma cells. Inhibition of VEGFR-1 abrogated multiple myeloma cell proliferation and motility, suggesting that the functional interaction of VEGF-A with its cognate receptor is essential for the growth of primary multiple myeloma cells. Collectively, our results suggest that stromal-dependent paracrine and intracrine VEGF-A/VEGFR-1 signaling contributes to human primary multiple myeloma cell growth and therefore, VEGFR-1 blockade is a potential therapeutic strategy for the treatment of multiple myeloma.

Cytokine preconditioning promotes codifferentiation of human fetal liver CD133+ stem cells into angiomyogenic tissue.

BACKGROUND: CD133 (AC133) is a surface antigen that defines a broad population of stem cells, including myogenic and endothelial progenitors. CD133+ cells are rare in adult tissues, and the factors that support their differentiation into mature angiomyogenic cells are not known. These hurdles have hampered the use of CD133+ cells for therapeutic purposes. Because human fetal liver is a rich source of CD133+ cells, we sought to identify the growth factors that promote codifferentiation of these cells into angiogenic and myogenic cells. METHODS AND RESULTS: Human fetal liver CD133+ and CD133- cell subpopulations were cultured with 5'-azacytidine or vascular endothelial growth factor (VEGF165) and/or brain-derived nerve growth factor (BDNF). CD133+ but not CD133- cells from human fetal liver codifferentiated into spindle-shaped cells, as well as flat adherent multinucleated cells capable of spontaneous contractions in culture. The resulting spindle-shaped cells were confirmed to be endothelial cells by immunohistochemistry analysis for von Willebrand factor and by acetylated LDL uptake. Multinucleated cells were characterized as striated muscles by electron microscopy and immunohistochemistry analysis for myosin heavy chain. Presence of VEGF165 and BDNF significantly enhanced angiomyogenesis in vitro. Inoculation of cells derived from CD133+ cells, but not CD133- cells, into the ear pinna of NOD/SCID mice resulted in the formation of cardiomyocytes, as identified by immunostaining with cardiac troponin-T antibody. These cells generated electrical action potentials, detectable by ECG tracing. CONCLUSIONS: CD133 defines a population of human fetal liver cells capable of differentiating into both angiogenic and myogenic cells. Preconditioning of these CD133+ cells with VEGF165 and BDNF enhances the angiomyogenesis. CD133+ fetal liver cells ultimately may be used for therapeutic angiomyogenesis.

Impact of midtrimester dilation and evacuation on subsequent pregnancy outcome.

OBJECTIVE: This study was undertaken to evaluate the impact of second-trimester dilation and evacuation (D&E) on subsequent pregnancy outcome. STUDY DESIGN: Medical record review of 600 patients undergoing midtrimester (14-24 weeks) D&E from 1996 to 2000 and evaluation of subsequent pregnancy outcome. Mann Whitney U, Spearman rho, and chi(2) tests were used in statistical analysis with a P value <.05 considered significant. RESULTS: Ninety-six subsequent pregnancies were identified, including 12 first-trimester spontaneous abortions, 1 second-trimester fetal death, 1 ectopic pregnancy, and 5 elective terminations. Seventy-seven pregnancies resulted in the delivery of a live-born infant at a median gestational age of 39.0 weeks. Five pregnancies (6.5%) were complicated by spontaneous preterm birth. Patients delivered preterm had an earlier gestational age at D&E (18.0 vs 20.0 weeks, P =.02) and a trend toward less preoperative cervical dilation (2.0 vs 3.0 cm, P =.09) than patients delivered at term. CONCLUSION: Second-trimester D&E is not a risk factor for midtrimester pregnancy loss or spontaneous preterm birth. Preterm delivery in future gestations appears less likely when greater preoperative cervical dilation is achieved with laminaria, possibly because of a decrease in cervical trauma.

Dilation and evacuation at >or=20 weeks: comparison of operative techniques.

OBJECTIVE: The objective of this study is to compare the relative safety of 2 techniques for surgical abortion late in the second trimester.Study design Retrospective review of patients who underwent surgical abortion at >or=20 weeks' gestation at our hospital from June 1996 through June 2003. Records were reviewed to determine whether the technique used was dilation and evacuation or intact dilation and extraction. Subsequent pregnancies at our hospital were identified, and obstetric outcomes were recorded. Categorical data were compared with Fisher exact test and chi(2) analysis. Continuous data were compared with Mann-Whitney U test. RESULTS: Three hundred eighty-three patients met inclusion criteria. Intact dilation and extraction was performed in 120 cases, and dilation and evacuation was used in 263. Intact dilation and extraction was associated with higher parity, later gestational age, and more preoperative cervical dilation. There was no difference in procedure time or estimated blood loss in the 2 groups. Complications occurred in 19 cases (5.0%), and occurred with similar frequency in the 2 groups. We identified 62 subsequent pregnancies. There were no second-trimester miscarriages. Spontaneous preterm birth occurred in 2 of 17 (11.8%) pregnancies in the intact dilation and extraction group, compared with 2 of 45 (4.4%) in the dilation and evacuation group (P=.30). CONCLUSION: Outcomes appear similar between patients undergoing dilation and evacuation and intact dilation and extraction after 20 weeks' gestation. Subsequent obstetric outcomes are similar between the 2 groups. The technique for surgical abortion should be determined by the physician on the basis of intraoperative factors.